Arc welding system



Sept. l 1, 1928.

J. F. K. HARMS ARC WELDING SYSTEM Filed Feb. 24, 1 927 FIG.2.

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PATENT OFFICE.

UNITED STATES JOHANNESFRANiS KAREL HARMS, OF AMSTERDAM, NETHERLANDS, ASSL IGNOB TO J'ONKHEER MEESTER DOCTOR JELLE BOELOF CLIFFORD KOCQ VAN BREUGEL, OF

DRIEBERGEN, NETHERLAN DS.

ARC WELDING' SYSTEM.

Application filed February 2 1,: 1927, Serial No. 170,584, and in the'Netherauds February 11, 1927.

Arc-welding` by means of alternating current has the advantage, over are-weiding' by means of direct current, in that the Welding apparatus may be connected, through a trans- 5 former, to the eccentric network. However, since the Welding apparatus consumes a Very large current, it is 'impossible to obtain an approximately uniform load on the phases of a rotary 'current network, which fact has led many electricity works to exclude Welding apparatus from the current supply.

Various suggestions have already been offered to avoid this inconvenienc Inter alia, it has been proposed to use; for the Welding operation, an electrode composed of twobars or rods insulatedfrom one another and to .connect the three phases of the network to the workpiece and to the two said electrodes, respectively. In this case, au additional 'arc is formed between the two electrodcs, but this is rather a disadvantagethan an advantage.

The object of my invention is a Welding apparatus, which does not cause any appreciable variation in the load of the network and which, moreover, produces a a remarkably 'steady and*`uni form are. lVith this object in view,-' I use two transformers, eachconnected to two phases of the 'network, and to couple the secondary windings to derive the 0 Welding current therefrom. The annexed drawing illustrates, diagrammatically andby way of example only, three different embodiments of my invention. In the 'embodiments shown in Figs. 1 and 2, the' secondary windings 1 of both -transformers are connected in the same manner as are the primary windings 3. According to Fig. 1, one Welding cable 2 is connected to one end; the second Welding cable 4`to the other 40 end of the Combined secondary windingz, but according to Fig. 2, the secondary Windings v 1 have their ends connected together and to only one of the 'Welding cables 4, the other Welding cable 2 being connected to a point intermediate between the secondary windings. In the arrangement shown in Fig. 3,

'units, or be combined into one aggregate. I

recom'nend the use of an auxiliary resistance whch IS put n and out of crcut alternately with the Welding arc, whereby sudden variatons n the voltage are avoided. n lVhat I claim 'is:--

1. An alternating current arc welding` apparatus, comprising a plurality of transforners, each of said transformers having: a pr mary winding and a secondary winding, sa d primary winding of each transformer being adapted to be connected across each phase of a poly phase' alternating current source of supply, said secondary Windings beng in series with each other, and a work circuit connected to said secondary windings.

2. An alternating current are Welding apparatus, comprising a plurality of transformers, each of said transformers having a primary winding and a secondary winding, said primary winding of each transformer being adapted tov be connected across each phase of a poly phase alternating current source of supply, said secondary windings being connected in parallel, and a work circuit connected to said secondary windings.

3. An alternating current arc Welding apparatus, comprising a plurality of transormers, each of said transformcrs having a primary winding and a secondary Winding,

said primary winding of each transformer being adapted to be connected across each phase of a poly phase alternating current source of supply, said secondary windings being connected in reverse parallel relation with each other, and a work circuit connected'.

to said secondary windings.

In testimony whereof I aflix my Signature.

' JOHANNES FRANS KAREL HARIS. 

